What is concentration in terms of a substance in a volume?

Concentration refers to the amount of a substance present within a specific volume of solution or mixture. It quantifies how much of that substance exists compared to the total volume being considered, allowing for an understanding of the substance's prevalence in that space. This measurement can be expressed in various units, such as moles per liter, grams per liter, or percentages, depending on the context.

The other options do not accurately capture the definition of concentration. The weight of the substance is relevant but does not indicate how that weight relates to the volume in which it is found. The volume of the container, while important to assess concentration, is not the same as the concentration itself, which ties the amount of substance to that volume. The temperature of the substance can influence its behavior and properties but does not define concentration either. Thus, the definition of concentration as the amount of a substance in a given volume is clear and directly addresses the concept in question.